국립 부경대학교

부경대 연구진, 리튬-황 전지 효율 향상 방안 찾았다
- 금속유기골격체 이온수송 메커니즘 밝혀 … 英왕립화학회 학술지 게재

△ 정성철 교수, 전태곤 연구원 사진

국립부경대학교 정성철 교수(물리학과) 연구팀이 리튬-황 이차전지 효율을 높일 수 있는 금속유기골격체(Metal organic framework) 이온수송 메커니즘을 밝히는 데 성공했다.

정 교수와 전태곤 연구원(물리학과·나노과학기술연구소)은 HKUST-1 금속유기골격체 기반 분리막이 리튬다황화물의 이동은 차단하면서 리튬이온만을 효과적으로 통과시키는 메커니즘을 원자 수준에서 규명해냈다.

금속유기골격체는 이차전지, 수소저장, 촉매, 센서, 약물전달 등의 분야에 활용되는 미세다공성 물질이다.

리튬-황 이차전지는 리튬다황화물이 분리막을 통과해 양극과 음극 사이를 반복적으로 왕복하는 셔틀현상이 고질적인 문제였다.

정 교수 연구팀은 제일원리계산 시뮬레이션 연구를 통해 금속유기골격체 기공의 크기뿐만 아니라 금속유기골격체를 통과하는 이온 또는 분자의 용매화 구조가 분리막을 통과할 수 있는 중요한 요인이라는 사실을 규명했다. 금속유기골격체의 활성부위와 이온 또는 분자 간 화학결합 유무도 중요한 요인으로 나타났다.

정 교수는 “이번 연구 결과는 리튬다황화물의 셔틀현상 해결은 물론, 일반적인 액체전해질 기반 금속-이온전지의 금속유기골격체 분리막을 설계할 때도 매우 유용한 정보가 될 수 있다.”라면서, “일반적인 미세다공성 물질에서 표적물질만의 선택적 이동과 차단을 제어하는 데도 도움을 줄 수 있을 것으로 기대한다.”라고 밝혔다.

이번 연구는 과학기술정보통신부(중견연구)의 지원을 받아 진행됐으며, 영국 왕립화학회(Royal Society of Chemistry)가 발간하는 화학·물리·재료 분야의 세계적 국제학술지 <Journal of Materials Chemistry A>(인용지수=12.732) 온라인판에 최근 게재됐다. <부경투데이>

PKNU researchers have found a way to improve the efficiency of lithium-sulfur batteries

- Discovering the ion transport mechanism of metal-organic frameworks

A research team led by Professor Jung Sung-Chul (Dept. of Physics) at Pukyong National University succeeded in discovering the ion transport mechanism of a metal organic framework that can increase the efficiency of lithium-sulfur secondary batteries.

Professor Jung and researcher Jeon Tae-Gon (Department of Physics · Research Center for Nano Science and Technology) have identified the mechanism at the atomic-level by which the HKUST-1 metal-organic framework-based separator blocks the movement of lithium polysulfide while effectively allowing only lithium ions to pass through.

The metal-organic framework is a microporous material used in the fields of secondary batteries, hydrogen storage, catalysts, sensors, and drug delivery.

Lithium-sulfur secondary batteries have a chronic shuttle phenomenon in which lithium polysulfide passes through the separator and repeatedly reciprocates between the positive and negative electrodes.

Professor Jung's research team identified the fact that not only the size of the pores of the metal-organic framework, but also the solvation structure of ions or molecules passing through the metal-organic framework are important factors that can pass through the separation membrane through the first principle calculation simulation study. The presence or absence of chemical bonds between active sites and ions or molecules of the metal-organic framework was also found to be an important factor.

Professor Jung said, "The results of this study can be very useful information not only to solve the shuttle phenomenon of lithium polysulfide, but also to design a metal-organic framework separator for a general liquid electrolyte-based metal-ion battery," he added, "I expect that it will also be helpful in the process of controlling the selective movement and blocking of only the target material in general microporous materials."

This research was conducted with the support of the Ministry of Science and ICT (middle-level research), and has been recently published online by the Royal Society of Chemistry, <Journal of Materials Chemistry A> (Citation Index = 12.732). <Pukyong Today>